My vet was definitely confused by the amount of meds thrown at my girl. We reduced meds down to the amoxicillan only and he took bloodwork and a fecal sample. He said he'd like to re-do the x-ray if we need to, but wanted to save me a bit of money by seeing what the bloodwork and samples turn up first. Apparently the x-ray wasn't the best, either. Sigh.
Anyway, she continued to perk up after passing the bloody mucus, and has eaten enough to get her strength back. The current suspicion is that the mucus and blood is coming from the reproductive tract, because her actual stool looks normal at a glance, and she is not bleeding from the digestive tract. She has a history of prolapse and bleeding (pretty heavily) with egg-laying during seasonal hormonal changes so this makes sense to me. I don't know what this will mean for her prognosis or treatment, but for now, she's back outside enjoying the dirt. We will continue to separate her to ensure she's continuing to eat and poop regularly, but it doesn't look like she's in any imminent danger while we await test results.